I'd like to drive that car and see how it performs. Yes, turbo kits were availabe for the 616 in Europe. Lots of people with 616's in motorhomes used them. I talked to a gentleman on the ferry to France who had added one to his motorhome and really liked it.
I have an aftermarket turbo on my Cat 3208. I think I would be sure to use a pyrometer.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13